Bias-cutting machine



July 24, 1934. s v wrrz 1,967,486

BIAS CUTTING MACHINE Filed NOV. 21. 1932 3 Sheets-Shet l I F35 IHVENT'OE3 4.7 jfe a/ en O Vennem/z,

4 TQENEY July 24, 19 4- s. o. VENNEWITZ BIAS CUTTING MACHINE 3Sheet-Sheet Filed Nov. 21. 1932 July 24, 1934.

s. o. VENNEWITZ 1,967,486

BIAS CUTT ING MACHINE Filed NOV. 21. 1932 -3 Sheets-Sheet 5 TG F/4E YPatented July 24, I934 BIAS-CUTTIN G MACHINE Stephen 0. Yennewitz,Fairfield, Ill., assignor to Sexton Manufacturing Company, Fairfield,Ill., a corporation of Illinois Application November 21, 1932, SerialNo. 643,676

1'1 Claims. (Cl. 16473) This invention relates to a certain new anduseful improvement in bias cutting machines and has for its prime objectthe provision of a machinefor automatically converting a web of fabricinto a continuous bias-cut strip.

My invention has for a further object the provision of a machine forautomatically cutting fabric on the bias while the fabric is in motion,

the fabric being folded for providing a doubled l0 strip which isstitched into'tubular form and then altemately and in successiondiagonally cut in its opposite walls, the slitted fabric when unfoldedhaving the form of a continuous strip of bias-cut material.

My invention has for a still further object the provision of a machinefor automatically cutting bias-strips from continuously moving webs offabric material stitched in tubular form, the stitching-operation beingeifected synchronously with the bias-cutting operation for regulatingthe fineness of the stitches.

And with the above and other objects in view, my invention resides inthe novel features of form, construction, arrangement and combination ofparts presently described and pointed out in the claims. V

In the accompanying drawings (three sheets) Figure 1 is a perspectiveview of a bias-strip cutting machine embodying my invention;

Figure 2 is an enlarged fragmentary partly sectional side elevationalview of the machine, taken from the sewing-head or right hand sidethereof;

Figure 3 is an enlarged sectional view of the machine, takenapproximately along the line 3-3, Figure 2, illustrating thefabric-feeding and bias-cutting mechanisms;

Figure 4 is a fragmentary top-plan view illustrating one of the biasmargin-cutting mecha nisms;

Figure 5 is a fragmentary sectional view taken approximately along theline 5-5, Figure 4;

Figure 6 is a fragmentary top-plan view illustrating the other biasmargin-cutting mechanism; v

Figure '7 is a side elevational view of the machine parts shown inFigure 6, other portions of the machine being broken away;

' Figure 8 is a fragmentary plan view of the bias cut fabric-tube as itemerges from the machine; and

Figure 9 is a reduced fragmentary plan view of the bias cut stripresulting from and on unfolding of the bias cut tube of Figure 8.

- Referring now more in detail and by reference characters to thedrawings, which illustrate a preferred embodiment of my invention, Adesignates generally a continuous web of doubled preferably woven clothor other flexible fabric, that is to say, a web of woven or textilefabric overlapped lengthwise, as at a folded margin 1, to 00 include anupper fold or wall 2 and a lower fold or wall 3 with the free margins 4of the walls 2, 3, disposed in registration. In practice, the doubledweb A is preferably wound into a roll or bolt B, which is mounted on aspindle or mandrel 5, in turn, conveniently removably journaled on apair of suitable standards 6 upstanding from a floor or other suitablesupport adjacent a work-bench or table C. Preferably the mandrel 5 isprovided with a wheel 7 with which may be frictionally en-. 7o

gaged a brake-shoe 8 for tensioning the web A as occasion may require,the web A being led from the bolt B over a suitable roller 9 rotarilysupported on arms 10 projecting obliquely upwardly from the standards 6and then over the table C to the cutting-machine proper, as best seen inFigure 1.

The table C includes suitable standards 11, and fixed at an end on thetable C is an arm 12, whose opposite end extends laterally between thefree web-margins 4 for supporting a wall dividso ing core or frame D,flatwise intermediate the upper and lower walls 2, 3, of thedoubled-web A. The frame D, which is of approximately rectangular shapeand in width is substantially equal to the width of the doubled'web, A,is spaced 35 above the table C for both guiding the web A in its passageover the table C and spacing the walls 2, 3, one from the other forpurposes shortly appearing.

Also mounted on the table C, is a sewing-head E of conventionalconstruction, of which it may here merely be said that the head E issuitably driven by a chain and sprocket arrangement 13 from and by aprime-mover or motor 14 supported on an adjacent standard 11, as will beunderstood from Figure 1. However, in the present instance, and for thepurposes of my invention, the usually provided stitch-regulator andfeeder mechanism is omitted from the sewinghead E, the stitch regulationand strip-feeding being obtained by other means presently described, anditvwill be observed that the arm 12 is spaced forwardly of thesewing-head 6, whereby, as the web A is drawn through the sewinghead E,the free margins 4 of the doubled web A are engaged by the presser-foote of the head E, which stitches the web-margins 4 together as by a lineof stitching 15, the doubled web A then taking a tubular form and theso-formed tube A then flatwise enveloping the core or web spacing frameD, as best seen in Figure 1.

Supported for rotation in a suitable framework which includes a pair ofsuitably spaced standards 16, 16', disposed to the rear of the table 0,are parallel horizontally disposed shafts 17, 18, upon which arearranged opposed upper and lower feed-rollers 19, 20, respectively,disposed in alignment with, and suitably spaced rearwardly from, therear margin of the wallspacing frame D for gripping engagement .of thetubular strip A therebetween.

The shafts 1'7, 18, are lengthwise extended through the standard. 16,which is adjacent the sewing-head E, and carry respective similarmeshing gears 21, 21', whereby the rollers 19, 20, are synchronouslydriven with the same peripheral speed. The shaft 1'7 also carries a gear22, which meshes with a gear 23 mounted on the adjacent end of ajack-shaft 24 suitably mounted in bearings, as at 25, supported on aframework 26 disposed in the rear of the table C. At its other end, theshaft 24 extends to a point opposite the drive-end of the sewing-head E,the drive-shaft 27' thereof being connected to the shaft 24 by means ofa-suitable mechanical connection generally indicated at 28, and as bestseen in Figure 2, whereby the rollers 19, 20, are also driven insynchronism with the sewinghead E.

The rollers 19, 20, thus engaging the tubularstrip A, draw on thedoubled web A for moving or feeding the same to and through thesewinghead E for application of the stitching 15 to the web-margins 4,and it will, therefore, be seen that, by providing pairs of gears 22,23, of different relative dimensions or ratios, the peripheral speed ofthe rollers 19, 20, may be varied relatively to the speed of operationof the sewing-head E, whereby the character of the stitch 15,produced-by the sewing-head E, may be regulated from a coarse to a finestitch, as occasion may require.

' F designates a bias cutting mechanism, which includes a guide-rod 29horizontally supported by and between the standards 16, 16, over theplane of the tubular-strip A, forwardly of the feed-rollers 19, 20, andin parallel relation with, and closely to the rear of, the reartransverse margin of the wall-spacing frame or plate D. Slidable on therod 29 transversely of the machine, is a carriage 30, on which ismounted for oscillation in a vertical plane a cutter-head 31,

and carried by the cutter-head 31 for movement at right angles to thefeed of the strip A and preferably along the rear margin of the core orplate D, is a knife or blade 32 having a length for engagement only withthe upper strip-wall 2 when in vertically disposed cutting or slittingposition, as best seen in Figure 3. The knife 32 has its cutting edge onits right-hand side, reference being made to Figure 3, and as a whole isobliquely disposed on its vertical axis at an angle of 45, more or less,to the center-line of the strip A ,for normal cutting-engagement withthe upper wall 2 of the strip A as the latter departs from the frame D,as will presently more fully appear.

Upstanding from the carriage 30, is a yoke 33,

; which loosely embraces an elongated cylindercam 34 fixed on a shaft 35journaled for rotation in and between the standards 16, '16'.' The yoke33 is provided with a lug or cam-follower 36 having co-operativeengagement alternately with oppositely threaded spiral or helicalcam-grooves 37, 38, suitably formed in the periphery of the cylinder 34and extending from end to end thereof, the grooves 37, 38, suitablycrossing one another during their traverse of the length of the cylinder34 and communicating one with the other at the respective opposite endsof the cylinder 34, as best seen in Figure 3.

The shaft 35 projects suitably through the standard 16 and carriesa'gear 39, which, through an idler-gear 40, is driven by and with thegear 21. Accordingly, when the lug 36 is engaged with .the cam-groove37, the carriage 30 and the carried cutter 32 are caused to travel at auniform speed transversely of the strip A coincidently with longitudinalmovement of the strip A past the plane of movement of the knife 32,whereby the latter effects a cut or slit, as at a, at an angle of 45,more or less, to the length of the tube A, in the upper wall 2 thereof,as shown in Figure 8, the cutter 32 moving from left to right whenlooking in the direction of strip movement and as shown in Figure 3.

Disposed below the plane of the strip A, inopposing relation withrespect to-the mechanism F, is a like cutting mechanism F, whichincludes similarly a knife 32' upstanding from an oscillatory head 31supported on a carriage 30' slidably mounted on a horizontal guide rod29. The cutter 32' has its cutting edge on its left-hand side, referencebeing made to Figure 3, and the cutter .32 as a whole is likewiseobliquely disposed on its vertical axis at an angle of 45, more or les,to the center-line of the strip A, though oppositely to the cutter 32,the cutter 32 being normally disposed for engaging the'lower wall 3 ofthe tubular-strip A.

The carriage 30 similarly carries a depending yoke 33' loosely embracinga cylinder 34' mounted on a shaft 35' journaled for rotation in andbetween the lower portion of the standards 16, 16', the yoke 33'carrying a lug 36' co-operating with a pair of cam-grooves 37', 38,provided in the periphery of the cylinder 34', and the shaft 35 carryinga gear 39' which is driven. through an idler gear 40, by and with thegear 21' mounted on the roller-shaft 18. Accordingly, when the lug 36 isengaging the cam-groove 37, the carriage 30 and its carried cutter 32'are caused to travel transversely of the tube A coincidently withlongitudinal movement of the strip A past the plane of movement of thecutter 32, whereby the latter effects a cut or slit a at an angle ofmore or less, in the lower wall 3 of the tubular strip A, the cutter 32'then moving from right to left when looking in the direction ofmovementof the strip A, as shown in Figure 3.

Fixed preferably on the cylinder-cam 34 at the so-designated right-handend thereof, that is to say, adjacent the standard 16, is a radiallyprojecting cam-tooth or lug 41 for intermittent engagement, for purposespresently appearing, with a plunger 42 slidably mounted in and throughsuitable vertically registering bracket-bearing 43 low, the horizontalaxis of the head 31 when for the similar or like parts of the firstdescribed the cutter 32 is disposed in vertical strip slitting position,as'best seen in Figure 3. The several parts are so arranged that, as thecutter 32 arrives at the terminus of its strip slitting movement, thep1unger42 is downwardly shifted by the cam-lug -41 and impinges the pin46' for rotarily actuating the head 31 for disposing the cutter 32 inoblique or non-cutting position, as shown by dot-dash lines I in Figure3. Meanwhile, the carriage 30 compressively engages a suitablebuffer-spring 48 mounted on the rod 29 adjacent the standard 16, whichurges the lug 36 to now enter the reverse cam-groove 38 for returningthe carriage 30 and its now inoperative cutter 32 to the left-hand sideof the machine. As the carriage 30 approaches its left-hand terminalposition, the pin 47 of the head 31 engages a concave cam-face 49 on thesuitably projecting end of a bracket supported on the adjacent standard16', whereby the head 31 is reversely rotarily actuated for disposingthe cutter 32 again in vertical strip-slitting position, as shown bydot-dash lines II in Figure 3.

Meanwhile, the carriage 30 compressively engages a buffer-spring 51mounted on the rod 29 adjacent the standard 16, which in like mannerurges the lug 36 to now enter the cam-groove 38 for traversing thecarriage 30 across the ma chine, the knife 32 then again cutting in thestrip A another slit (1 parallel to and from the first slit a, andso onrepetitively during operation of the machine, the carriage 30 travelingalternately first to the right and then to the left' in the machine, theknife 32 being in operative position for cutting a slit a in the upperwall 2 of the strip A when the carriage 30 is. shifted in one orright-hand direction across the strip, and the knife 32 being spacedfrom the strip A or in inoperative non-slitting position when thecarriage 30 is shifted in reverse or left-hand direction across thestrip for return of the knife 32 to its initial position. During suchcarriage and cutter movement, the strip A is also traveling at rightangles to the movement of the cutter 32. Hence, as the result of suchcomplementary movements, the slits a, a are formed obliquely ordiagonally or on a bias through the strip-wall.

Likewise fixed on the cylinder-cam 34' at the so-designated left-handend thereof, is a tooth 41' for co-operation with aplunger 42'reciprocable in bearings 43' and biased normally downwardly by a spring44, the plunger 42' carrying a lug 45' for impingement by the cam-tooth41' on each revolution of the cam 34.

The cutter-head 31' is also provided with pins 46', 47', the pin 46'being engageable by the plunger 42' for rotarily actuating the head 31'as the cutter 32' arrives at the end of its cutting stroke for disposingthe cutter 32' in oblique or non-cutting position, the carriage 30'engaging a buffer-spring 48' mounted on the rod 32' adjacent thestandard 16' for urging the lug cutting-mechanism F.

The carriages 30, 30', travel across the tubular strip A in unison, thatis to say, in the same direction at the same time, the mechanism F beingeffective for automatically cutting the bias-slits a in the upper wall 2during movement or travel of the carriage 30 from left to right in themachine, and the mechanism F being effective for automatically cuttingthe bias-slits a in the lower wall 3 during movement or travel of thecarriage 31' from right toleft in the machine.

As will be seen from Figure 3, the cutter or blade 32, at thecommencement of its strip-slitting stroke, is by the engagement of thepin 47 with the cam-face 49 disposed in vertical cutting position andremains in such position for cutting a slit a substantially from thefolded margin 1 across the tube-wall 2 until the pin 46, at the oppositeside of the machine, is engaged by the reciprocated plunger 42,whereupon the cutter 32 is swung into inoperative non-cutting position,such action occurring in such manner that the cutter 32 is lifted fromthe strip before the slit a is continued to and through the stitchedmargin 4 of the tube. In like but reverse manner, the cutter 32' effectsa slit from adjacent the stitched margin 4 of the tube to, but notthrough, the opposite folded margin 1 thereof.

Thus there is an uncut portion of the margin 4 between the terminationof the slit a and the beginning of a slit a, the former being alsospaced a short distance ahead of the latter, due to the movement of thestrip A during the interval of time elapsing from the lifting of theknife 32 from the tube A to the engagement of 'the knife 32' therewith.A similar hiatus exists between a slit a and a slit a at the foldedmargin 1 of the 'tube, as best seen in Figure 6.

' The tube-walls 2, 3, therefore, remain connected at the marginalportions 1, 4, of the tubular strip A for even travel of the now biasslitted tube A" to and through the feed rolls 19, 20, the cut tube A"being delivered from the rolls 19, 20, to and upon a rearwardlyextending horizontal table 52 supported suitably by and between thestandards 16, 16', as best seen in Figures 2 and 5.

For consequently continuously connecting the slits a, a, a pair ofmechanisms G, G, are provided, the tube-margin cutting mechanism G beingdisposed rearwardly of and at the righthand side of the rolls 19, 20,and including a drive sprocket 53 mounted on the end of the shaft 18,and a pair of verticallyspaced upper I and lower idler or guidesprockets 54; 55, respectively, suitably supported on the standard 16.Over the sprockets 53, 54, 55, is trained a suitable flexible endlesselement or chain 56, the upper run thereof from the sprocket 53 to thesprocket'54 having a suitable upward and rearward inclination, and thechain 56 carrying an inwardly presented lug 57' depending from the iii)swinging the lever 60 at its other or inner end downwardly and forwardlyacross the upper face of the block 59, a suitable spring or othertensional member 61 normally biasing the lever 60 in upwardly swungposition, as best seen in Figure 4.

On its upper face, the block 59 is provided with a forwardly anddownwardly inclined way 62, in which is reciprocably mounted a plunger63 suitably, as by a pin-and-slot arrangement 64, connected to the innerend of the lever 60 for actuation of the plunger 63 by and with thelever 60 responsive to engagement of the latter by the chain-lug 5'7. l

At its lower end, the plunger 63 carries a knife 65 directed toward thetube-margin 4, the length of the chain 56 being selected such that, atproper intervals of the operation of the machine, the lever 60 isrecurrently actuated for correspondingly shifting the knife 65 in thedirection of inclination of the way 62 for penetrating the tube margin4, the knife 65 passing through the tube-walls 2, 3, for momentarilyresiding in a suitable pocket 66 provided in the table 52, as best seenin Figures 4and 5.

As has been said, the termination of a slit a in the top wall 2 isspaced from the margin 4 and likewise from the beginning of thesucceeding slit a in the lower wall 3 of the tube A". The knife 65,however, has its cutting edge obliquely disposed or receding from itsinside point 67 outwardly and rearwardly, whereby the point 67 of theknife 65 meets the termination of the slit a, and, since the tube movesrearwardly as the knife 65 advances forwardly the receding edge of theknife 65 effects a diagonal cut or continuation of the slit 0. forconnecting the same, through the margin 4, with the beginning of thesucceeding slit (1', as best seen in Figure 4.

The opposite margin cutting mechanism G is disposed rearwardly of and atthe left-hand side of the feed rolls 19, 20, and similarly comprises adrive-sprocket 53 mounted on the adjacent end of the shaft 18, andvertically spaced idler sprockets 54', 55', over which is trained achain 56', the upper run of which has a suitable rearwardand downwardinclination, and the chain 56 carrying an outwardly presented lug 57upstanding from its upper run, as best seen in Figure 7.

Adjacent the standard 16', the table 52 supports a depending guide-block59' having its lower face inclined forwardly and upwardly inregistration with an opening 68 provided in the table 52, the opening 68being likewise in registration with the margin 1 of the slit tubularstrip A. Pivotally supported on the lower face of the block 59, is alever 60 having its outer end engageable with the chain-lug 57', thelever 60 being normally biased in non-operative position by a spring61'.

On its lower face, the block 59 is provided with a way 62', in which isreciprocably mounted a plunger 63 suitably operably connected, as at64', to the lever 60' and carrying a knife 65' having an oblique cuttingedge and an advancing inside point 67', the knife 65' being shiftable inthe direction of inclination of the way 62' on actuation of the lever60" by the chain-lug 57' for penetrating the tube-margin 1 at suitableintervals. Likewise, the knife 65 passes through the tube-walls formomentarily residing in a pocket 66' provided ina member or bracket 69suitably supported from the table 52 for overhanging the tube-margin 1,substantially in the manner set forth in connection with the mechanism Gand as best seen in Figures 6 and 7.

However, on the folded margin 1 of the tube A", it is desired to connectthe lower slit a in the lower tube wall 3 with the slit (1 in the uppertube-wall 2. Consequently the knife 65' is brought upwardly against thelower wall 3 of the tube A" for effecting a diagonal cut or continuationof the slit a for connecting the same through the margin 1 with the slita similarly as described in connecting a slit (1 with a succeeding slita.

In use and operation, therefore, it will be seen that a suitably foldedor doubled web of fabricmaterial A is stitched along its longitudinalmargins 4 for forming a tube A, which is then, while in motion throughthe machine, diagonally cut, as by the series of slits a, a,respectively, alternating in direction in the also respective oppositewalls of the tube A, the slitted tube A" being then further operatedupon, while also in motion through the machine, for connectingrespective slits a, a, to and through the margins 1, 4, of the tube A",the resulting product comprising a helically-cut fabric-tube which may,in any convenient manner not here shown, be unfolded from its tubularform or condition into a continuous strip Af' of diagonally conjoinedrhomboidal fabric sections 70 of bias-cut material, as best seen inFigure 9.

I might add that, if desired, the bias slitted fabric-tube A may beWound while folded on a mandrel, not shown, for subsequent unwinding atsuch time as it may be desired to unfold the tube A" for obtaining thebias-strip A', which latter may also conveniently be longitudinallydivided for the ready formation of socalled bias-tape '11, as suggestedin Figure 9.

The machine may be economically operated with little labor and has beenfound exceedingly efficient in the performance of its intendedfunctions.

It will be understood that changes and modifications in the form,construction, arrangement, and combination of the several parts of themachine may be made and substituted for those herein shown and describedwithout departing from the nature and principle of my invention.

Having thus described by invention, what I claim and desire to secure byLetters Patent 1. In a bias cutting-machine, in combination, means formoving a strip in approximately a flat plane, a carriage reciprocablecrosswise of the moving strip, a cutting-blade mounted for movementwith, and being also pivotally shiftable relatively to, the carriage,mechanism for reciprocating the carriage and its carried blade, andmeans for pivotally disposing the blade in operative position forslitt'ng engagement with the moving strip during travel of the carriagein one direction and for disposing the blade into inoperative non-stripslitting position during travel of the carriage in the other direction.

2. In a bias cutting-machine, in combination, means for moving a stripin approximately a fiat plane, a reciprocable carriage, a cutter-headmounted both for movement with and for oscillation on the carriage, acutting-blade carried by the head, a reciprocable plunger actuable insynchronism with reciprocations of the carriage for oscillation of thehead in one direction at one end of carriage travel for endwisedisposing the blade for slitting engagement with the moving strip'duringtravel of the carriage in one direction, and a cam co-operable with thehead .for oscillating the same in opposite direction on engagement ofthe head with the cam at the opposite end of carriage travel forobliquely disposing the blade into inoperative non-strip slittingposition during travel of the carriage in the other direction.

3. In a bias cutting-machine, in combination, means for moving a flatdouble wall strip in ap proximately a fiat plane, a pair of shiftablecutters, and mechanism for reciprocating the cutters crosswise of, andfor alternately-in succession disposing the cutters for slittingengagement with respective walls of the moving strip.

4. A bias cutting-machine, in combination, means for moving a tubularstrip, cutters disposed for travel on the respective opposite sides ofthe moving strip, mechanism for reciprocating the cutters crosswise ofthe moving strip, and means for successively shifting the cutters atrespective alternations thereof into and out of position. for slittingengagement with the moving strip.

5. A bias cutting-machine including means for moving in approximately afiat plane a strip comprising flatwise superposed and marginallyconnected walls, and mechanism comprising a plurality of shiftableknives successively operable for cutting the superposed strip-walls andtheir connecting marginal portions While the same are in motion forforming a series ,of connected diagonal slits alternating in directionin the respective walls of the strip.

6. In a bias cutting-machine, means for moving a flattened tube offabric-material, means for cutting the opposite sides of the moving tubefor forming a series of marginally disconnected diagonal slitsalternating in direction in the respective walls of the tube, andreciprocable knives disposed for cutting engagement with the respectivemargins of the moving slitted tube for connecting adjacent ends ofopposed diagonal slits.

'7. In a bias cutting-machine, means for moving a flattened tube offabric material,- means for cutting the opposite sides of the movingtube for forming a series of marginally disconnected diagonal slitsalternating in direction in the respective walls of the tube, a pair ofreciprocable knives shiftably disposed for cutting engagement with therespective margins of the moving slitted tube for connecting adjacentends of alternate diagonal slits, and means for actuating said knives insynchronism with the cutting means.

8. In a bias cutting-machine, in combination, means for moving a stripin approximately a flat plane, a shiitable cutter, and mechanism forshifting the cutter during movement of the strip and. in a path disposedcrosswise of the path of movement, and limited to a distance less thanthe width, of the moving strip for slitting the moving strip on a linewhich terminates short of the opposite margins of the strip.

9. In a bias cutting-machine, in combination, means for moving a doublewall strip in approximately a fiat plane, opposed cutters mounted formovement on opposite sides of the strip, and

mechanism for shifting the respective cutters during movement of thestrip and in respective paths disposed crosswise of the path ofmovement, and each limited to a distance less than the Width, of themoving strip for slitting the moving strip on respectivelines whichterminate short of the opposite margins of the strip.-

10. A bias cutting-machine including, in commovable cutters for severingthe opposite strip-l walls and their marginally connecting-portions, andmeans for synchronously actuating the cutters for forming a connectedseries of diagonal slits oppositelydisposed in the respective walls ofthe moving strip.

11. A bias cutting-machine including, in combination, means for moving afiat double wall strip in approximately a fiat plane, a plurality ofmovable cutters, and means for synchronously actuating the cutters forforming a connected series of diagonal slits oppositely disposed in therespective walls of the moving strip, some of said cutters being inopposed relation and mounted for movement on opposite sides and.crosswise of the strip and others of said cutters being endwisereciprocable transversely through the strip.

12. A bias cutting-machine including, in combination, means for moving afiat double wall strip in approximately a fiat plane, a plurality ofmovable cutters, and means for synchronously j actuating the cutters forforming a connected series 01 diagonal slits oppositely disposed in therespective walls of the moving strip; some of said cutters being inopposed relation and mounted for limited reciprocatory movement onopposite sides and crosswise of the strip intermediate the oppositemargins of the walls thereof and others 01' said cutters being endwisereciprocable transversely through the opposite margins of the strip.

13. In a bias-cutting machine, in combination, 11

means for moving a strip in approximately a flat plane, a shiftablecarriage, a cutter mounted for movement with and for oscillation on thecarriage, mechanism for reciprocating the carriage for shifting thecutter alternately in opposite movement with andfor oscillation on thecarriage, mechanism for reciprocating the carriage for shifting thecutter crosswise of the moving strip, and means for oscillating thecutter relatively to and at the opposite ends of travel of the carriagefor disposing the cutter in operative position for slitting engagementwith the moving strip during travel of the carriage in one direction andfor disposing the cutter into inoperative non-strip slitting positionduring travel of the I carriage in the other direction.

15. In a bias cutting-machine, in combination,

means for moving a strip in approximately a fiat plane, a shiftablecutter, and mechanism for reciprocating the cutter in the same planecrosswise of the path of travel of the strip and while the strip is inmovement for slitting the moving strip 5 on a line which terminatesshort of the opposite margins of the strip.

16. In a bias cutting-machine, in combination,

means for moving a strip in approximately a fiat plane, a shiftablecutter, and mechanism including a rotary cylindrical cam forreciprocating the cutter in the same plane crosswise of the path oftravel of the strip and while the strip is in move- .ment for slittingthe moving strip on aline which including a cylindrical cam comprisinga, pair of oppositely threaded grooves connected at the respective endsof the cylinder, a carriage for the cutter, a yoke on the carriageengageable with said grooves, and resilient members for biasing thecarriage at the respective ends of said grooves for alternate engagementof the yoke with said grooves.

STEPHEN O.VENNEWITZ.

